Bolt burst into a trot. Sam's heart jumped into his throat.
Up and down, up and down, he bounced in the saddle. His feet flew out of the stirrups.
The fence and the barn and Grandpa flashed by.
"Whoa!" yelled Sam. "Whoa!"
Grandpa stepped in front of Bolt. He grabbed the reins and pulled Bolt to a stop.
Sam took a huge breath. "I'm getting off!" he said.
He slid off the horse. It was a long way to the ground. His legs wobbled. He thought Grandpa would be disgusted with him.
But Grandpa looked pleased.
"Not bad for your first time," he said.

Sam is horrified when his mother leaves him for two weeks on his grandfather's ranch. Grandpa has a lot of rules, and Sam isn't happy about staying with him. Things get worse when Sam meets a huge scary horse called Bolt. But as Sam struggles to learn how to ride Bolt, he grows to appreciate both his grandfather and life on the ranch..